Washington State - Our in state little brother. It's a natural rivalry, the big city school vs. the rural school, the educated business men vs. the farmers, the big research school vs. the veterinary school. The schools first met on the grid iron in 1900, they've played 104 times and the UW leads the series 67-31-6. Wazzu is just like the typical semi retarded little brother, they want to be big and important like the older brother, but they'll never have the natural advantages of the big brother. The rivalry has lost some steam lately, partly do to both teams being less than good, and partly do to the rise of Oregon. Sark vs. Leach should put this rivalry right back where it belongs!
Oregon - They are our ugly cousin to the south, we really didn't mind them so much in the past, they were just another nobody we'd beat up on every year. Then their rich Uncle decide to give them his fortune and our ugly cousin suddenly thought they were the real deal, but in reality they are just pot smoking, rule breaking hippies, who are blessed with a rich Uncle. The rivalry also started in 1900, they've played 104 times and the UW leads the series 58-41-5. Washington also holds the record for the largest victory winning 66-0 in 1974. Oregon's recent success, combined with a rather young and immature fan base and the ugliest uniforms in the history of college football, has rocketed them up to the status of very hated rival.
Oregon State - Oregon State is like that cousin you often forget you have, but when you see them the competition heats up. OSU, like WSU, suffers from a location that limits their resources, but I'd take Corvallis over Pullman any day of the week. After doing some brief research, trying to find the overall school records, I quickly gave up and realized that UW vs. OSU just doesn't have the necessary hatred to overtake Oregon vs. UW. This is exactly why OSU doesn't like Washington, we have quiet the tendency to overlook them and relegate them to the back of the bus.
California - Cal is that cousin you actually respect and might actually like to some extent, but then you found out that your wife once dated this cousin and your cousin hates you because she choose you over him. Although Cal hasn't been a "big" rival of Washington in the past, it's a rivalry that is picking up steam rather quickly. If losing to the Willingham Huskies in Seattle in late November wasn't enough to drive them crazy, but losing your most loved and loyal coach to Darth Sarkisian would push anybody over the edge.
My Opinion - It's a very tough choice. How do you determine your biggest rival? Is it based off of history or base off of pure hatred? WSU has the history of being the biggest rival, but it's much easier to hate Oregon. It's well known that I have a lot of respect for Coach Leach, I would love to see WSU win 11 games a year and lose to an undefeated UW. Oregon on the other hand, I hope gets slaughtered by the NCAA for being the cheating pot smokers that they are, the football program struggles to recover and ends up being terminated by the university. If you can't tell, in my mind Oregon has become our biggest rival.
My apologies to the good fans of our rival fan bases (no apology to the bad or immature fans), due to highly unusual work hours, a highly messed up circadian rhythm, which is a byproduct created by a lack of continuous sleep, this post might be more "testy" than I would normally write!